Letter to the Editor
BeppoSAX follow-up search for the X-ray afterglow of GRB970111
Muller 2, 3,
in 't Zand 3,
Frontera 4, 5,
Dal Fiume 4,
M. Orlandini 4,
A.N. Parmar 6,
Received 6 January 1998 / Accepted 3 March 1998
The BeppoSAX satellite has recently opened a new way towards the solution of the long standing gamma-ray bursts' (GRBs) enigma, providing accurate coordinates few hours after the event thus allowing for multiwavelength follow-up observational campaigns.
The BeppoSAX Narrow Field Instruments observed the region of sky containing GRB970111 16 hours after the burst. In contrast to other GRBs observed by BeppoSAX no bright afterglow was unambiguously observed. A faint source (1SAXJ1528.1+1937) is detected in a position consistent with the BeppoSAX Wide Field Camera position, but unconsistent with the IPN annulus. Whether 1SAXJ1528.1+1937 is associated with GRB970111 or not, the X-ray intensity of the afterglow is significantly lower than expected, based on the properties of the other BeppoSAX GRB afterglows. Given that GRB970111 is one of the brightest GRBs observed, this implies that there is no obvious relation between the GRB gamma-ray peak flux and the intensity of the X-ray afterglow.
Key words: Gamma rays: bursts X-rays: bursts
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© European Southern Observatory (ESO) 1998
Online publication: March 30, 1998